Cationically modified cellulose ethers and their use in personal care compositions have been known for many years.
U.S. Pat. No. 3,472,840 discloses quaternary nitrogen-containing cellulose ethers having a degree of polymerization (number of anhydroglucose repeat units) of 50 to 20,000, preferably 200 to 5,000, and their use as flocculents for paper pulp, coal dust, silica or clay or as a retention aid in the manufacture of paper.
The International Patent Publication WO 01/48021 discloses highly charged cationic cellulose ethers which are substituted with at least about 3.0 wt. % cationic substituent. These cellulose ethers are recommended for use in personal care applications, for example for enhanced substantivity to skin and hair.
Cellulose ethers which comprise 1.5-2.2 weight percent of cationic nitrogen are sold commercially by Amerchol under the trademark UCARE™ Polymers JR. Cellulose ethers which comprise 0.8-1.1 weight percent of cationic nitrogen are sold commercially by Amerchol under the trademark UCARE™ Polymers LR. These polymers have found wide use as water-soluble substantive conditioners for hair care and skin care products.
Although personal care compositions comprising a cationically modified cellulose ether have found wide acceptance, it would be still desirable to provide personal care compositions with improved properties.
Personal care compositions, such as hair care compositions and particularly skin care compositions, often comprise a moisturizing agent, such as sunflower seed oil. It is highly desirable that much of the moisturizing agent remains on the skin after it has been treated with the skin care or hair care composition and after the composition has rinsed off the skin. Therefore, one object of the present invention is to provide new personal care compositions which leave a high level of moisturizing agent, such as sunflower seed oil, on the skin after it has been treated with the personal care composition.
Furthermore, cationically modified cellulose ethers are widely used as conditioning agents, often in combination with insoluble active ingredients such as silicones, in hair care compositions. The conditioning properties of these products can be assessed by measuring the amount of work, which is required to comb through a hair tress treated with conditioning shampoo versus a control that does not comprise a conditioning agent. It is highly desirable to provide even greater reduction in wet combing work to enhance the consumer's positive usage experience when detangling and combing hair after shampooing. Therefore, another object of this invention is to provide new personal care compositions, such as hair care compositions, that deliver conditioning benefit, such as wet combing work reduction, to hair after it has been treated with the personal care composition.
Yet another object of the present invention is to provide new cationically modified cellulose ethers which are useful in such personal care compositions.